Injection molded ring binders provide a method of removably binding paper. One such binder is provided in EP A 0 704 322 which discloses a one-piece binder made of plastic using an injection molding process. To insert paper into the binder, the loops are first spread open using a binding machine. The spring force of the individual fingers allows the loops to close and hold the paper fast.
The disadvantage of this type of spine binder in private or semiprofessional use is that a binding machine must be used in order to insert sheets of paper for the first time or any time thereafter, making assembly inconvenient. Further, such a spine binder also has the disadvantage that a stack of sheets correspondingly bound cannot be turned over completely through 360.degree., since the dorsal part of the binder substantially prevents such a turning over of the sheets.